Intégration des aspects hydrologiques et socio-économiques pour la gestion d'un bassin versant : besoins et opportunités

[Departement_IRSTEA]RE [TR1_IRSTEA]GES / USAGESSustainable catchment management requires the integration of the hydrologic, environmental and socio-economic components that occur within the catchment. Most existing models deal individually with each component. Modeling of the components alone may not simulate the complete system effectively as physical/environmental and socio-economic systems have emergent properties which relate to the whole, and not merely to the sum of the parts. A realistic framework that integrates a range of models (hydrologic and socio-economic) and datasets will therefore provide the necessary platform for assessing the impacts of proposed policy and management strategies on livelihoods. This paper introduces a framework for the coupling of hydrologic and socio-economic models. The model framework will account for the interactions between water availability, farmer behavior, agricultural productivity, and will estimate the socio-economic gains from improvement in the allocation and efficiency of water use. The paper further suggests ways in which such models can be developed and used. The integration model will test and evaluate a given policy on the farmer income and the quality of livelihood outcomes. The approach aims to explore, rather than predict, the future and is not oriented towards optimization. By exploring alternative scenarios the user exercises choice of the best bet solutions of proposed policy and management practices. The model framework will be applied in the Olifants River Basin, South Africa at quaternary level (lowest water management area) as a case study for an in-depth investigation